Many house doors are secured with a deadbolt lock. This is a secondary lock that is installed on the door, separate from the lock in the door knob, to provide an extra measure of security. You may have come home and realised that you cannot find the key to your house's deadbolt. Instead of calling a professional locksmith to unlock the door, you can open the lock using a couple of paper clips.
Make a lock pick out of one paper clip by unbending it completely. With the second paper clip, form a tension wrench by unbending one end of it to make an "L" shape.
Place the tension wrench at the deadbolt's keyhole bottom, and insert it. Put the pick into the top of the keyhole.
Apply tension to the tension wrench, turning it slightly to the right or the left. The way the tension wrench is turned is based on the direction used to turn the deadbolt's key when it is in the lock.
Remove the pick quickly while applying tension to the tension wrench. When done properly, the pick rakes against the pins, simulating the movement of a key. This causes the lock to open.
It may take multiple attempts before you are able to open the lock.